In general, acoustic transducer is the device to output an acoustic signal which is received in electrical format, to convert an electrical energy into a mechanical energy due to voice coil which is existed in air gaps of magnetic circuit by Fleming's left-hand rule, i.e., when electrical signal containing various frequency apply to voice coil, it generates mechanical energy according to the current intensity and frequency amplitude, vibrates diaphragms then eventually generates acoustic pressure which can be noticed by human ears.
Such as this acoustic transducer is to generate acoustic pressure, forming air gaps with embodiment of the magnet and the upper plate inside of yoke, by connection of driver which consists of voice coil to develop magnetic flux inter-linkage in the air gap and diaphragms which is adhesive fixed on the frame.
Such as this acoustic transducer closely relates to volumetric displacement of the diaphragms. i.e., the output of transducer shall be increasing as the volumetric displacement is bigger. Thus, when to make higher output of acoustic transducer, it is necessary to expand the size of diaphragm, or increase rectilinear displacement of diaphragms, or increase the above both. According to these, up to now, transducer which consists of wide area diaphragms has been deployed to regenerate lower frequency acoustic.
But, to accommodate the diaphragms which have wide area, it causes additional expense and inefficiency because of big sized housing. Especially, there are difficulties for a slim acoustic transducer. For example, it was difficult for the conventional whooper speaker to adapt to slim electronic products such as plat panel television or computer monitor, because of its big volume.
Meanwhile, it is recently developed the linear array transducer apparatus, to drive a plurals of diaphragms through two driving rods. For example, “ACOUSTIC TRANSDUCER INCLUDING A PLURALS OF AXIAL ARRAY DIAPHRAGMS” is presented in REP. OF KOREA PATENT DISCLOSURE 10-2007-0035494.
As shown in FIG. 16, the conventional acoustic transducer is deployed with 1st driving rod and 2nd driving rod in inside of housing. And a plurality of 1st diaphragms is fixed at the above 1st driving rod and a plurality of 2nd diaphragms is fixed at the above 2nd driving rod. And the above 1st driving rod is connected with 1st driver and the above 2nd driving rod is connected with 2nd driver
Especially, in the conventional linear acoustic transducer, a plurals of 1st diaphragms and 2nd diaphragms are deployed above and below alternately at inside of housing. And, the above 1st and 2nd driving rod are parallel deployed each other at regular interval. And 1st driving rod is fixed penetrating 1st diaphragms and 2nd driving rod is fixed penetrating 2nd diaphragms. These conventional acoustic transducer can generate acoustic pressure, due to compression or expansion air between the above 1st diaphragms and 2nd diaphragms with simultaneous vibration of the above 1st driving rod and 2nd driving rod.
But, in the conventional linear acoustic transducer, it was difficult for kinetic energy which was generated from the above driver to deliver efficiently into the above driving rod and diaphragms because biased connection of driving rod between driver and the center of diaphragms, and it has collision sound problem due to the collision between voice coil and yoke because it was occurred eccentricity at voice coil which is deployed between yoke and magnet, and in serious case, there was a problem that voice coil was damaged.
According to this situation, recently, it is presented that the above driving rod connects with driver and the center of diaphragms through biased deployment of driver and diaphragms. But, this conventional acoustic transducer had problems; it was difficult for acoustic transducer to be slim because of bigger diameter of housing due to the deployment two driving rods in a regular interval, to be complicated housing structure. Also, in the conventional acoustic transducer, there was output decreasing problem because two driving rods penetrate each diaphragm, causing leakage of acoustic pressure through penetrated hole at the above diaphragms when the air was pressured between the above diaphragms.